Hi,

I'm opening the issue to start a discussion about sharing the sourcemap configuration between rollup and plugins.

For example, here is a "classic" configuration. As a rollup user, I have to disable sourcemap option in rollup configuration, and for each plugins:

const babel = require('rollup-plugin-babel');
const commonjs = require('rollup-plugin-commonjs');
const nodeResolve = require('rollup-plugin-node-resolve');

module.exports = {
  input: './src/index.js',

  output: {
    file: './dist/bundle.js',
    sourcemap: false,
  },

  plugins: [
    nodeResolve(),

    babel({
      sourceMap: false,
    }),

    commonjs({
      sourceMap: false,
    }),
  ],
};

There are two kinds of plugins that need the sourcemap configuration: plugins that implement the transform and/or the transformBundle function.

@Rich-Harris Not sure what is the best way to implement it, but I would be happy to send a pull request if you have an idea.